Underfeed stoker



May 27, 1930. R. s. RILEY UNDER FEED sToKEE Filed April 22, 1922 2Sheets-Sheet l IN VEN TOR.

R. 's. RILEY UNDER FEED STOKER May 27, 1930.

Filed April 22. 1922 2 Sheetsj-Sheet 2 @MJF I N VEN TOR.

Patented May 27, 1930 UNITED ASTATES vPMLNT onirica ROBERT SANFORDRILEY, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO RILEY STOIKERCORPORATION, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MAS-SACHUSETTS UNDERFEED STOKER Application filed April 22,

This invention relates to a mechanical stoker of the underfeed type inwhich fuel is supplied through a plurality of retorts, each receivingfresh fuel at its upper or front end and discharging ash and refuse fromthe f rear end thereof onto an overfeed 'grate eX- Ltension and thenceto the ash'dump.

Adjacent retorts are separated by air-con ducting side walls supportingthe usual tuyre blocks and it is one of the objects of my invention toseparately control the Vair supply for different parts orsections ofthese side ywalls and tuyre blocks andthe overfeed I grate section. ThisfeatureV of my invention is of particular importance in very largestokers in which the condition of the fuel bed may vary greatly indifferent parts of the .furnac-e, rendering it very desirable to be able"to independently increase or decrease the air pressure at any desiredpoint.

In one form of my invention, the sectional overfeed grate mounted at therear of the retort has its middle portion fixed and the side portionsmounted to move with the retort side walls. Itis a second obj ect of myinvention to provide a separate air supply for the fixed overfeed grateelements and particularly to combine this separate air supply for theiiXed overfeed grate portion with the independent air supply fordifferent sections of the side walls.

Furthermore, my invention contemplates provision for` suitable airsupply for the rocking ash discharge or dumping plates at the rear ofthe retorts and overfeed grates, and in the pref-erredeform, l associatewith the air supply for the dumping plates the air supply for themovable side elements of the overfeed grates.

An additional object of my invention is to provide means to preventoverheating of the clinker grinding and ash removing mechanism of myimproved furnace'.

My invention further relates to certain arrangements and combinations ofparts which 1922. Serial No. 556,011.

will be hereinafter described and more particularly pointed out in theappended claims.

A preferred form of my invention is shown in the drawings in which Fig.1 is a partial plan view of my improved stoker;

e Fig. 2 is 'a sectional elevation taken along the line 2-2 in Fig. l; y4

Fig. 3 is apartial sectional elevation taken along the line 3 3 inFig. 1. n

Fig. 4 is a detail view of the driving anism of the clinker grind-er;and

Fig. 5 is a sectional elevation ofthe clinker grinder, taken along theline 5--5 in Fig. 4.

mech- Referring to the drawings, I have yshown` parts of a Stoker which,in its general arrangement and construction, closely resembles a wellknown commercial type ,and in'- cludes a hopper 2O connected to a.cylinder k21 from which coal or other fuel is forced by a ram 22 througha feed chute or casing 23 into the upper end of the associated retort.The casing 23 is mounted in the front wall 24 of the furnace and the ram22 is regularly reciprocated by a connecting rod 25 actuated by a crankshaft 26.r The shaft 26 is provided with a worm wheel 27 engaged anddriven by a wormvnot shown, the mechanism Vthus far described being ofthe usual constructionand forming'no part of my present invention.

The retorts are inclined rearwardly and downwardly and are provided withside walls 28 preferably having lost motion connections 29 with the ram22. The side walls 28 ar-e thus reciprocated with the ram 2,2 duringv aportion only of each stroke of the ram. The extent of movement of theside walls may be increased as desired by placing U-shaped collars 30 onthe' lost motion vconnections 29, thereby reducing the lost motionbetween the parts. The side walls of adjacent retorts are spaced apartsufficiently to form air passages, the construction and function ofwhich will be'hereinafter described; l

`My improved Stoker is provided with air admitting ash discharge platespivotally mounted at the rear of the retorts and connected by an airconduit 61, to an air chamber 62 extending beneath the several retorts.A damper 63 may be provided tocontrol the flow of air from the chamber62 to the conduit 61.

A main wind trunk 64 is connected to the chamber 62 bya passa-ge 65,controllcd'by a damper 66. The wind trunk 64 is also connected to aVsecond air chamber 67by a passage 68 controlled by a damper 69.

The separate side walls 28 of the retorts deline air passages Vthroughwhich air is supplied` to the tuyre blocks 71. vPartitions 72 divide theside wall passages into upper and lower portions, the upper portionbeing in direct communication with the air chamber 67 and the lowerportion being similarly connected with the air chamber 62. The tuyreblocks are thus disposed in two groups and the air pressure for eachgroup may be separately controlled by means of the dampers 66 and 69.

A series of overfeed grates are provided bctween the rear ends of theretorts and the ash discharge plates 60'and these overfeed gratesareshown as each comprising side portions 73 and 74, and an intermediateportion 75. The intermediate portion 75 is fixed in position and servesas a continuation of the stationary'bottom of the retort, while the sideportions 73 and 74 are movable with the retort side walls 28.

The middle portion v7 5 is Vseparately connected by a passage 76 to thewind trunk 64, the flow of air to the grate portion 7 5 being controlledby a sliding damper 77. The air for the side overfeed grate elements 73and 74 is preferably drawn from the air space 61 to which the ashdischarge plates 60 are'connected. Plates 78 (FigQ) separate theoverfeed grate elements 73 and 74 from the lower air passage between theside walls 28.

Provision Vis thus made for supplying air at any desired pressure to theu per or lower sections of the tuyre blocks an to the middle section ofthe overfeed grate, and provision is alsoV made for supplying air at thepressure of the air chamber 62 or less/to the ash discharge plates 60and to the overfeedgrate elements 73 and 74. f

The stoker shown in Figs. 1 and-2 also'em- Vbodies a clinker grinder orrollr 80 and a second series of ash discharge plates 81, mounted upon.the rear or bridge wall 82, and receiving air from a passage 83.The'diseharge plates 81 are preferably arranged in sections which may bemoved separately or in small groups by the actuating mechanism shown,which comprises a shaft 85 having arms -86 connected by'links 87 to theplates 81 and having additional arms 88 connected by links 89 to'lifterrods 90. y

A hand wheel 91 is threaded on each rod 90 and a 4spring 92. isinterposed between ythe struction of these parts vof the grinding umechanism form no part of my present invention, and a completedescription thereof will be found in my prior application Serial No.386,848, filed J une 5, 1920. The roll may be intermittently actuated bya pawl 98 (Fig. 4) and ratchet wheel 99, the pawl being connected by alink 100 to actuating means not shown.L I v It is found that the clinkergrinding rolls are often seriously distorted by the eXtreme heat towhich they are occasionally subjected, and, as stated,`it is an obj ectof my invention to provide means to prevent such overheating of therolls. For this purposeV the ends-of the tube or ypipe 95 are left openor are only partially closed by ringsgor flanges 101 and a water pipe102 is introduced into one en'd of the pipe 95. nozzle 103, controlledby a valve 104, suitably connected by an arm 105 and linki106 to asleeve 107. This sleeve is sli-dabler on 'the pipe 102 and is controlledin position by any suitable thermostat such as a bellows thermostat 108of well known construction, one end "of which is secured to a collar 109lirXed on the pipe 102.

The parts are so arranged that expansion and contraction of thethermostat, due to increase and decrease of temperature respectively,will move the sleeve 107 and turn the valve 104 and control the escapeof water either the upper or lower portions of the sidel walls and tuyreblocks and also on the fixed portion of the overfeed grate may belraised or lowered as desired and without reference to the pressure inthe other portions ofthe stoker. y v

I havealso provided for a suitable supply of air, at any pressure notgreater than that on the lower set of tuyre blocks, for the-airadmittingash discharge plates and for the movable portions of the overfeed grate.In addition to this, I have 'provided novelmeans for preventingdistortionand injury to the grinder rolls.- i v Lic It will be evidentthat changes and modifications can be made in my invention withoutdeparting from the spirit and Scope thereof 4as Set forth in the claims,and I do not wish to be otherwise limited to the details hereindisclosed, but what I claim is l. An underleed stoker comprising wallsdefining a retort having a Astationary bottom, an overfeed grate Sectionhaving a stationary middle portion, serving as an extension of theretort bottom, side portions which are movable lengthwise of the Stokerrelative to the stationary middle portion and means for actuating themovable portions of the grate.

2. An underfeed Stoker comprising walls defining an underfeed retorthaving a Stationary bottom, an overfeed grate section having tuyreopenings therein, said section having a stationary middle portion whichserves as an extension of the retort bottom and side portions which aremovable lengthwise of the stoker, means for supplying air under pressureto said Overfeed grate section and means for actuating the movableportions of the grate.

3. An underfeed Stoker comprising a stationary bottom and movable sidewalls forming a retort therebetween, tuyre blocks on the side walls, astationary overfeed grate section having tuyre openings therethroughwhich serves as an extension of the retort bottom and overfeed gratesections on each side of said stationary section which are movablelengthwise of the stoker with said retort side walls.

l. An underfeed Stoker comprising retorts having stationary bottoms andlongitudinally reciprocable side walls arranged to provide an air spacebeneath the Stoker, tuyre structures surmounting said side walls andadapted to receive air from said Space and deliver it to the retorts, atransverse partition eX- tending between the reciprocable side wallswhich divides said space into forward and rear compartments, both ofwhich deliver air to the retort tuyres, an air duct, means formingseparate passages directly connecting said duct with each of saidcompartments, and sep arately adjustable damper means controlling theair flow through each passage, whereby the pressure in eithercompartment maybe regulated independently of the pressure in the other.

5. An underfeed stoker comprising walls defining retorts having tuyrestherebetween, an overfeed grate extension at the rear end of saidretorts having tuyre openings therethrough, means including a transversepartition extending beneath the retorts and forming forward and rearcompartments, each adapted to supply air to part of the tuyres betweenthe retorts, partitioning means forming an air compartment beneath theoverfeed grate extension for Supplying air thereto, an air duct, meansforming separate passages directly connecting said duct with each ofsaid compartments, and separately adjustable damper means controllingthe air tlow through each passage, whereby the pressure in anycompartment may be higher or lower than the pressure in any othercompartment.

In testimony whereof I have hereunto affixed my signature.

ROBERT SANFORD RILEY.

